Glacial Wall

Concentrate

Mnemonic Wall

Defender
When Mnemonic Wall enters, you may return target instant or sorcery card from your graveyard to your hand.

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Counterspell

Island

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Quicksilver Wall

Defender (This creature can't attack.)
{4}: Return Quicksilver Wall to its owner's hand. Any player may activate this ability.

Amaranthine Wall

Defender
{2}: Amaranthine Wall gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Clear the Mind

Target player shuffles their graveyard into their library.
Draw a card.

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Sleep

Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.

Quick Study

Wall of Lost Thoughts

Defender
When Wall of Lost Thoughts enters, target player mills four cards.

River's Rebuke

Return all nonland permanents target player controls to their owner's hand.

Steel Wall

Moonring Island

({T}: Add {U}.)
Moonring Island enters tapped.
{U}, {T}: Look at the top card of target player's library. Activate only if you control two or more blue permanents.